[Boost-bugs] [Boost C++ Libraries] #9734: Wrong check of mmap() return value in coroutine stack allocator

Subject: [Boost-bugs] [Boost C++ Libraries] #9734: Wrong check of mmap() return value in coroutine stack allocator
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-03-04 03:40:20

#9734: Wrong check of mmap() return value in coroutine stack allocator
------------------------------------+-----------------------
 Reporter:  Tianlong Wu <rockuw@…>  |      Owner:  olli
     Type:  Bugs                    |     Status:  new
Milestone:  To Be Determined        |  Component:  coroutine
  Version:  Boost 1.55.0            |   Severity:  Problem
 Keywords:                          |
------------------------------------+-----------------------
 In boost source
 /libs/coroutine/detail/standard_stack_allocator_posix.cpp:120, it has the
 following snippet:
 {{{#!c
     void * limit =
 # if defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)
     ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1,
 0);
 # else
     ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 # endif
     ::close( fd);
     if ( ! limit) throw std::bad_alloc();

 }}}

 It assumes that mmap() returns 0 on fail. However when mmap() fails, the
 return value is NOT 0, but (void*)-1 instead. This wrong check will bypass
 the throw and let the error pass down, leading to confusing error message
 seen by the user.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9734>
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